Houston Suspension Bridge, 2001

Private Client, Houston, TX
Satellite View of Bridge Location (resolution not high enough to see bridge.) View Larger Map

Houston Bridge upon completion, August 2001

USE:  Pedestrian

SPAN:  66 Feet

TRAVEL WIDTH:  4 Feet

TOWERS:  12'9" Tall, W10 x 39 weathering steel

ANCHORS:  1.5" Dixie Helical Screw Anchors

MAINLINES:  1" Bridge Strand

 

 

Bridge Builder Keith Monohan

 

 

 

This Sahale suspension bridge was installed for a private client on an estate of several acres in northwest Houston, TX.  Located off Memorial Drive, mediterranean style buildings at the home frame a swimming pool and forested ravine along the north shore of Lake Carter.  The owner desired a bridge across the ravine to link the core area of his property to a play/recreation area on the opposite side.  This project had numerous logistical challenges, not unlike many Sahale remote area projects.  Protection of the grounds and environment, particularly trees, were foremost objectives in the owner's mind.  Accordingly, installation of the bridge employed many proven sensitive area construction techniques for moving bridge materials and machinery over, through, and around vegetation and landscape infrastructure.  

Adapting a suspension bridge design to the site constraints was particularly challenging as the proximity of the house to the ravine was such that the desired bridge alignment did not accord enough space beyond the tower for anchoring the mainlines at a location sufficiently far enough from the tower to assure the cables described equal departure angles at the tower top.  To accommodate this constraint, Sahale developed a modified suspension/cable stay configuration for the bridge that anchored the mainlines using fully adjustable bridge sockets at the tower top and stay cables from the tower top to the main anchors.  This allowed a much steeper backstay angle than normal (albeit with correspondingly higher axial forces in the cable) and permitted the main anchors to be installed much nearer the bridge towers than is conventionally the case.  For main anchors Sahale avoided the site disturbance of excavation by using Dixie Helical Screws, turning them into the Houston clay with an excavator-mounted hydraulic torque motor to a depth exceeding 20 feet and an installation torque of approximately 8500 foot pounds.  Helical screws were similarly used for vertical bearing under the concrete abutments.

In addition to the unique hybrid cable stay/suspension design of the tower top, this bridge incorporated numerous Sahale engineered bridge features, including Sahale suspender clamps and bars, horizontal tension cable railing system, and under-deck tension cables.  Other client specified features included a treated southern yellow pine deck, thick rope hawser hand rail, and heavy black polypropylene fish net fence system.  The completed bridge is flexible, dynamic, and exciting, and reported by the owner to be a top attraction for youth and adults alike at his many private functions.

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